23 files changed, 387 insertions, 275 deletions

diff --git a/src/crepe/api/Animator.cpp b/src/crepe/api/Animator.cpp
index 4ce4bf0..203cef3 100644
--- a/src/crepe/api/Animator.cpp
+++ b/src/crepe/api/Animator.cpp
@@ -1,5 +1,5 @@
 
-#include "util/Log.h"
+#include "util/dbg.h"
 
 #include "Animator.h"
 #include "Component.h"
diff --git a/src/crepe/api/BehaviorScript.cpp b/src/crepe/api/BehaviorScript.cpp
index d22afdf..af7572c 100644
--- a/src/crepe/api/BehaviorScript.cpp
+++ b/src/crepe/api/BehaviorScript.cpp
@@ -10,6 +10,6 @@ BehaviorScript::BehaviorScript(game_object_id_t id, Mediator & mediator)
 
 template <>
 BehaviorScript & GameObject::add_component<BehaviorScript>() {
-	ComponentManager & mgr = this->component_manager;
-	return mgr.add_component<BehaviorScript>(this->id, mgr.mediator);
+	ComponentManager & mgr = this->mediator.component_manager;
+	return mgr.add_component<BehaviorScript>(this->id, this->mediator);
 }
diff --git a/src/crepe/api/BehaviorScript.hpp b/src/crepe/api/BehaviorScript.hpp
index b9bb1e2..353d5e2 100644
--- a/src/crepe/api/BehaviorScript.hpp
+++ b/src/crepe/api/BehaviorScript.hpp
@@ -2,8 +2,6 @@
 
 #include <type_traits>
 
-#include "../util/Log.h"
-
 #include "BehaviorScript.h"
 #include "Script.h"
 
@@ -11,7 +9,6 @@ namespace crepe {
 
 template <class T, typename... Args>
 BehaviorScript & BehaviorScript::set_script(Args &&... args) {
-	dbg_trace();
 	static_assert(std::is_base_of<Script, T>::value);
 	this->script = std::unique_ptr<Script>(new T(std::forward<Args>(args)...));
 
diff --git a/src/crepe/api/CMakeLists.txt b/src/crepe/api/CMakeLists.txt
index 8f84f06..18d6942 100644
--- a/src/crepe/api/CMakeLists.txt
+++ b/src/crepe/api/CMakeLists.txt
@@ -13,7 +13,7 @@ target_sources(crepe PUBLIC
 	Animator.cpp
 	BoxCollider.cpp
 	CircleCollider.cpp
-	LoopManager.cpp
+	Engine.cpp
 	Asset.cpp
 	EventHandler.cpp
 	Script.cpp
@@ -46,7 +46,8 @@ target_sources(crepe PUBLIC FILE_SET HEADERS FILES
 	EventHandler.h
 	EventHandler.hpp
 	Event.h
-	LoopManager.h
+	Engine.h
+	Engine.hpp
 	Asset.h
 	Button.h
 	UIObject.h
diff --git a/src/crepe/api/Camera.cpp b/src/crepe/api/Camera.cpp
index 179dc18..9befc3f 100644
--- a/src/crepe/api/Camera.cpp
+++ b/src/crepe/api/Camera.cpp
@@ -1,4 +1,4 @@
-#include "util/Log.h"
+#include "util/dbg.h"
 
 #include "Camera.h"
 #include "Component.h"
@@ -6,10 +6,8 @@
 
 using namespace crepe;
 
-Camera::Camera(game_object_id_t id, const ivec2 & screen, const vec2 & viewport_size,
-			   const Data & data)
+Camera::Camera(game_object_id_t id, const vec2 & viewport_size, const Data & data)
 	: Component(id),
-	  screen(screen),
 	  viewport_size(viewport_size),
 	  data(data) {
 	dbg_trace();
diff --git a/src/crepe/api/Camera.h b/src/crepe/api/Camera.h
index 54d9a73..48f2ff2 100644
--- a/src/crepe/api/Camera.h
+++ b/src/crepe/api/Camera.h
@@ -30,7 +30,7 @@ public:
 		 * zoom < 1 --> zoom out
 		 * zoom > 1 --> zoom in
 		 */
-		double zoom = 1;
+		float zoom = 1.0;
 
 		//! offset postion from the game object transform component
 		vec2 postion_offset;
@@ -40,20 +40,15 @@ public:
 	/**
 	 * \brief Constructs a Camera with the specified ID and background color.
 	 * \param id Unique identifier for the camera component.
-	 * \param screen is the actual screen size in pixels
 	 * \param viewport_size is the view of the world in game units
 	 * \param data the camera component data
 	 */
-	Camera(game_object_id_t id, const ivec2 & screen, const vec2 & viewport_size,
-		   const Camera::Data & data);
+	Camera(game_object_id_t id, const vec2 & viewport_size, const Data & data);
 	~Camera(); // dbg_trace only
 
 public:
 	Camera::Data data;
 
-	//! screen the display size in pixels ( output resolution )
-	const ivec2 screen;
-
 	//! viewport is the area of the world visible through the camera (in world units)
 	const vec2 viewport_size;
 
diff --git a/src/crepe/api/Engine.cpp b/src/crepe/api/Engine.cpp
new file mode 100644
index 0000000..bbb4494
--- /dev/null
+++ b/src/crepe/api/Engine.cpp
@@ -0,0 +1,63 @@
+#include "../util/Log.h"
+
+#include "Engine.h"
+
+using namespace crepe;
+using namespace std;
+
+int Engine::main() noexcept {
+	try {
+		this->setup();
+	} catch (const exception & e) {
+		Log::logf(Log::Level::ERROR, "Uncaught exception in setup: {}\n", e.what());
+		return EXIT_FAILURE;
+	}
+
+	try {
+		this->loop();
+	} catch (const exception & e) {
+		Log::logf(Log::Level::ERROR, "Uncaught exception in main loop: {}\n", e.what());
+		this->event_manager.trigger_event<ShutDownEvent>();
+	}
+
+	return EXIT_SUCCESS;
+}
+
+void Engine::setup() {
+	this->loop_timer.start();
+	this->scene_manager.load_next_scene();
+
+	this->event_manager.subscribe<ShutDownEvent>([this](const ShutDownEvent & event) {
+		this->game_running = false;
+
+		// propagate to possible user ShutDownEvent listeners
+		return false;
+	});
+}
+
+void Engine::loop() {
+	LoopTimerManager & timer = this->loop_timer;
+	SystemManager & systems = this->system_manager;
+
+	while (game_running) {
+		timer.update();
+
+		while (timer.get_lag() >= timer.get_fixed_delta_time()) {
+			try {
+				systems.fixed_update();
+			} catch (const exception & e) {
+				Log::logf(Log::Level::WARNING,
+						  "Uncaught exception in fixed update function: {}\n", e.what());
+			}
+			timer.advance_fixed_elapsed_time();
+		}
+
+		try {
+			systems.frame_update();
+		} catch (const exception & e) {
+			Log::logf(Log::Level::WARNING, "Uncaught exception in frame update function: {}\n",
+					  e.what());
+		}
+		timer.enforce_frame_rate();
+	}
+}
diff --git a/src/crepe/api/Engine.h b/src/crepe/api/Engine.h
new file mode 100644
index 0000000..3145723
--- /dev/null
+++ b/src/crepe/api/Engine.h
@@ -0,0 +1,78 @@
+#pragma once
+
+#include "../facade/SDLContext.h"
+#include "../manager/ComponentManager.h"
+#include "../manager/EventManager.h"
+#include "../manager/LoopTimerManager.h"
+#include "../manager/ReplayManager.h"
+#include "../manager/ResourceManager.h"
+#include "../manager/SaveManager.h"
+#include "../manager/SceneManager.h"
+#include "../manager/SystemManager.h"
+
+namespace crepe {
+
+/**
+ * \brief Main game entrypoint
+ *
+ * This class is responsible for managing the game loop, including initialization and updating.
+ */
+class Engine {
+public:
+	/**
+	 * \brief Engine entrypoint
+	 *
+	 * This function is called by the game programmer after registering all scenes
+	 *
+	 * \returns process exit code
+	 */
+	int main() noexcept;
+
+	//! \copydoc SceneManager::add_scene
+	template <typename T>
+	void add_scene();
+
+private:
+	/**
+	 * \brief Setup function for one-time initialization.
+	 *
+	 * This function initializes necessary components for the game.
+	 */
+	void setup();
+	/**
+	 * \brief Main game loop function.
+	 *
+	 * This function runs the main loop, handling game updates and rendering.
+	 */
+	void loop();
+
+	//! Game loop condition
+	bool game_running = true;
+
+private:
+	//! Global context
+	Mediator mediator;
+
+	//! Component manager instance
+	ComponentManager component_manager{mediator};
+	//! Scene manager instance
+	SceneManager scene_manager{mediator};
+	//! LoopTimerManager instance
+	LoopTimerManager loop_timer{mediator};
+	//! EventManager instance
+	EventManager event_manager{mediator};
+	//! Resource manager instance
+	ResourceManager resource_manager{mediator};
+	//! Save manager instance
+	SaveManager save_manager{mediator};
+	//! SDLContext instance
+	SDLContext sdl_context{mediator};
+	//! ReplayManager instance
+	ReplayManager replay_manager{mediator};
+	//! SystemManager
+	SystemManager system_manager{mediator};
+};
+
+} // namespace crepe
+
+#include "Engine.hpp"
diff --git a/src/crepe/api/Engine.hpp b/src/crepe/api/Engine.hpp
new file mode 100644
index 0000000..f2fdc0a
--- /dev/null
+++ b/src/crepe/api/Engine.hpp
@@ -0,0 +1,12 @@
+#pragma once
+
+#include "Engine.h"
+
+namespace crepe {
+
+template <class T>
+void Engine::add_scene() {
+	this->scene_manager.add_scene<T>();
+}
+
+} // namespace crepe
diff --git a/src/crepe/api/GameObject.cpp b/src/crepe/api/GameObject.cpp
index 9ef4682..9b94cad 100644
--- a/src/crepe/api/GameObject.cpp
+++ b/src/crepe/api/GameObject.cpp
@@ -7,20 +7,17 @@
 using namespace crepe;
 using namespace std;
 
-GameObject::GameObject(ComponentManager & component_manager, game_object_id_t id,
-					   const std::string & name, const std::string & tag,
-					   const vec2 & position, double rotation, double scale)
+GameObject::GameObject(Mediator & mediator, game_object_id_t id, const std::string & name,
+					   const std::string & tag, const vec2 & position, double rotation,
+					   double scale)
 	: id(id),
-	  component_manager(component_manager) {
-
-	// Add Transform and Metadata components
-	ComponentManager & mgr = this->component_manager;
-	mgr.add_component<Transform>(this->id, position, rotation, scale);
-	mgr.add_component<Metadata>(this->id, name, tag);
-}
+	  mediator(mediator),
+	  transform(mediator.component_manager->add_component<Transform>(this->id, position,
+																	 rotation, scale)),
+	  metadata(mediator.component_manager->add_component<Metadata>(this->id, name, tag)) {}
 
 void GameObject::set_parent(const GameObject & parent) {
-	ComponentManager & mgr = this->component_manager;
+	ComponentManager & mgr = this->mediator.component_manager;
 
 	// Set parent on own Metadata component
 	RefVector<Metadata> this_metadata = mgr.get_components_by_id<Metadata>(this->id);
@@ -32,7 +29,7 @@ void GameObject::set_parent(const GameObject & parent) {
 }
 
 void GameObject::set_persistent(bool persistent) {
-	ComponentManager & mgr = this->component_manager;
+	ComponentManager & mgr = this->mediator.component_manager;
 
 	mgr.set_persistent(this->id, persistent);
 }
diff --git a/src/crepe/api/GameObject.h b/src/crepe/api/GameObject.h
index ff80f49..572ce3a 100644
--- a/src/crepe/api/GameObject.h
+++ b/src/crepe/api/GameObject.h
@@ -6,7 +6,9 @@
 
 namespace crepe {
 
-class ComponentManager;
+class Mediator;
+class Transform;
+class Metadata;
 
 /**
  * \brief Represents a GameObject
@@ -20,7 +22,7 @@ private:
 	 * This constructor creates a new GameObject. It creates a new Transform and Metadata
 	 * component and adds them to the ComponentManager.
 	 *
-	 * \param component_manager Reference to component_manager
+	 * \param mediator Reference to mediator
 	 * \param id The id of the GameObject
 	 * \param name The name of the GameObject
 	 * \param tag The tag of the GameObject
@@ -28,13 +30,20 @@ private:
 	 * \param rotation The rotation of the GameObject
 	 * \param scale The scale of the GameObject
 	 */
-	GameObject(ComponentManager & component_manager, game_object_id_t id,
-			   const std::string & name, const std::string & tag, const vec2 & position,
-			   double rotation, double scale);
+	GameObject(Mediator & mediator, game_object_id_t id, const std::string & name,
+			   const std::string & tag, const vec2 & position, double rotation, double scale);
 	//! ComponentManager instances GameObject
 	friend class ComponentManager;
 
 public:
+	//! The id of the GameObject
+	const game_object_id_t id;
+	//! This entity's transform
+	Transform & transform;
+	//! This entity's metadata
+	Metadata & metadata;
+
+public:
 	/**
 	 * \brief Set the parent of this GameObject
 	 *
@@ -68,12 +77,8 @@ public:
 	 */
 	void set_persistent(bool persistent = true);
 
-public:
-	//! The id of the GameObject
-	const game_object_id_t id;
-
 protected:
-	ComponentManager & component_manager;
+	Mediator & mediator;
 };
 
 } // namespace crepe
diff --git a/src/crepe/api/GameObject.hpp b/src/crepe/api/GameObject.hpp
index a6b45b0..69f7d73 100644
--- a/src/crepe/api/GameObject.hpp
+++ b/src/crepe/api/GameObject.hpp
@@ -8,7 +8,7 @@ namespace crepe {
 
 template <typename T, typename... Args>
 T & GameObject::add_component(Args &&... args) {
-	ComponentManager & mgr = this->component_manager;
+	ComponentManager & mgr = this->mediator.component_manager;
 	return mgr.add_component<T>(this->id, std::forward<Args>(args)...);
 }
 
diff --git a/src/crepe/api/LoopManager.cpp b/src/crepe/api/LoopManager.cpp
index b5e5ff7..7a78019 100644
--- a/src/crepe/api/LoopManager.cpp
+++ b/src/crepe/api/LoopManager.cpp
@@ -65,6 +65,7 @@ void LoopManager::fixed_update() {
 	this->get_system<InputSystem>().update();
 	this->event_manager.dispatch_events();
 	this->get_system<ScriptSystem>().update();
+	this->get_system<ParticleSystem>().update();
 	this->get_system<AISystem>().update();
 	this->get_system<PhysicsSystem>().update();
 	this->get_system<CollisionSystem>().update();
diff --git a/src/crepe/api/LoopManager.h b/src/crepe/api/LoopManager.h
deleted file mode 100644
index 40e6b38..0000000
--- a/src/crepe/api/LoopManager.h
+++ /dev/null
@@ -1,122 +0,0 @@
-#pragma once
-
-#include <memory>
-
-#include "../facade/SDLContext.h"
-#include "../manager/ComponentManager.h"
-#include "../manager/EventManager.h"
-#include "../manager/LoopTimerManager.h"
-#include "../manager/Mediator.h"
-#include "../manager/ResourceManager.h"
-#include "../manager/SaveManager.h"
-#include "../manager/SceneManager.h"
-#include "../system/System.h"
-
-namespace crepe {
-/**
- * \brief Main game loop manager
- *
- * This class is responsible for managing the game loop, including initialization and updating.
- */
-class LoopManager {
-public:
-	LoopManager();
-	/**
-	 * \brief Start the gameloop
-	 *
-	 * This is the start of the engine where the setup is called and then the loop keeps running until the game stops running.
-	 * The Game programmer needs to call this function to run the game. This should be done after creating and adding all scenes.
-	 */
-	void start();
-
-	/**
-	 * \brief Add a new concrete scene to the scene manager
-	 *
-	 * \tparam T  Type of concrete scene
-	 */
-	template <typename T>
-	void add_scene();
-
-private:
-	/**
-	 * \brief Setup function for one-time initialization.
-	 *
-	 * This function initializes necessary components for the game.
-	 */
-	void setup();
-	/**
-	 * \brief Main game loop function.
-	 *
-	 * This function runs the main loop, handling game updates and rendering.
-	 */
-	void loop();
-
-	/**
-	 * \brief Per-frame update.
-	 *
-	 * Updates the game state based on the elapsed time since the last frame.
-	 */
-	virtual void frame_update();
-
-	/**
-	 * \brief Fixed update executed at a fixed rate.
-	 *
-	 * This function updates physics and game logic based on LoopTimer's fixed_delta_time.
-	 */
-	virtual void fixed_update();
-
-	//! Indicates whether the game is running.
-	bool game_running = false;
-
-private:
-	//! Global context
-	Mediator mediator;
-
-	//! Component manager instance
-	ComponentManager component_manager{mediator};
-	//! Scene manager instance
-	SceneManager scene_manager{mediator};
-	//! LoopTimerManager instance
-	LoopTimerManager loop_timer{mediator};
-	//! EventManager instance
-	EventManager event_manager{mediator};
-	//! Resource manager instance
-	ResourceManager resource_manager{mediator};
-	//! Save manager instance
-	SaveManager save_manager{mediator};
-	//! SDLContext instance
-	SDLContext sdl_context{mediator};
-
-private:
-	/**
-	 * \brief Callback function for ShutDownEvent
-	 *
-	 * This function sets the game_running variable to false, stopping the gameloop and therefor quitting the game.
-	 */
-	bool on_shutdown(const ShutDownEvent & e);
-	/**
-	 * \brief Collection of System instances
-	 *
-	 * This map holds System instances indexed by the system's class typeid. It is filled in the
-	 * constructor of LoopManager using LoopManager::load_system.
-	 */
-	std::unordered_map<std::type_index, std::unique_ptr<System>> systems;
-	/**
-	 * \brief Initialize a system
-	 * \tparam T System type (must be derivative of \c System)
-	 */
-	template <class T>
-	void load_system();
-	/**
-	 * \brief Retrieve a reference to ECS system
-	 * \tparam T System type
-	 * \returns Reference to system instance
-	 * \throws std::runtime_error if the System is not initialized
-	 */
-	template <class T>
-	T & get_system();
-};
-
-} // namespace crepe
-
-#include "LoopManager.hpp"
diff --git a/src/crepe/api/LoopManager.hpp b/src/crepe/api/LoopManager.hpp
deleted file mode 100644
index 266758a..0000000
--- a/src/crepe/api/LoopManager.hpp
+++ /dev/null
@@ -1,48 +0,0 @@
-#pragma once
-
-#include <cassert>
-#include <format>
-#include <memory>
-
-#include "../system/System.h"
-
-#include "LoopManager.h"
-
-namespace crepe {
-
-template <class T>
-void LoopManager::add_scene() {
-	this->scene_manager.add_scene<T>();
-}
-
-template <class T>
-T & LoopManager::get_system() {
-	using namespace std;
-	static_assert(is_base_of<System, T>::value,
-				  "get_system must recieve a derivative class of System");
-
-	const type_info & type = typeid(T);
-	if (!this->systems.contains(type))
-		throw runtime_error(format("LoopManager: {} is not initialized", type.name()));
-
-	System * system = this->systems.at(type).get();
-	T * concrete_system = dynamic_cast<T *>(system);
-	assert(concrete_system != nullptr);
-
-	return *concrete_system;
-}
-
-template <class T>
-void LoopManager::load_system() {
-	using namespace std;
-	static_assert(is_base_of<System, T>::value,
-				  "load_system must recieve a derivative class of System");
-
-	const type_info & type = typeid(T);
-	if (this->systems.contains(type))
-		throw runtime_error(format("LoopManager: {} is already initialized", type.name()));
-	System * system = new T(this->mediator);
-	this->systems[type] = unique_ptr<System>(system);
-}
-
-} // namespace crepe
diff --git a/src/crepe/api/ParticleEmitter.cpp b/src/crepe/api/ParticleEmitter.cpp
index 90b77a0..9a70334 100644
--- a/src/crepe/api/ParticleEmitter.cpp
+++ b/src/crepe/api/ParticleEmitter.cpp
@@ -1,11 +1,28 @@
 #include "ParticleEmitter.h"
+#include "api/Sprite.h"
 
 using namespace crepe;
+using namespace std;
 
-ParticleEmitter::ParticleEmitter(game_object_id_t game_object_id, const Data & data)
+ParticleEmitter::ParticleEmitter(game_object_id_t game_object_id, const Sprite & sprite,
+								 const Data & data)
 	: Component(game_object_id),
+	  sprite(sprite),
 	  data(data) {
 	for (size_t i = 0; i < this->data.max_particles; i++) {
-		this->data.particles.emplace_back();
+		this->particles.emplace_back();
 	}
 }
+
+unique_ptr<Component> ParticleEmitter::save() const {
+	return unique_ptr<Component>{new ParticleEmitter(*this)};
+}
+
+void ParticleEmitter::restore(const Component & snapshot) {
+	*this = static_cast<const ParticleEmitter &>(snapshot);
+}
+
+ParticleEmitter & ParticleEmitter::operator=(const ParticleEmitter & other) {
+	this->particles = other.particles;
+	return *this;
+}
diff --git a/src/crepe/api/ParticleEmitter.h b/src/crepe/api/ParticleEmitter.h
index b83fd61..626b356 100644
--- a/src/crepe/api/ParticleEmitter.h
+++ b/src/crepe/api/ParticleEmitter.h
@@ -1,7 +1,11 @@
 #pragma once
 
+#include <cmath>
 #include <vector>
 
+#include "system/ParticleSystem.h"
+#include "system/RenderSystem.h"
+
 #include "Component.h"
 #include "Particle.h"
 #include "types.h"
@@ -26,15 +30,18 @@ public:
 	 */
 	struct Boundary {
 		//! boundary width (midpoint is emitter location)
-		double width = 0.0;
+		float width = INFINITY;
 		//! boundary height (midpoint is emitter location)
-		double height = 0.0;
+		float height = INFINITY;
 		//! boundary offset from particle emitter location
 		vec2 offset;
 		//! reset on exit or stop velocity and set max postion
 		bool reset_on_exit = false;
 	};
 
+	//! sprite reference of displayed sprite
+	const Sprite & sprite;
+
 	/**
 	 * \brief Holds parameters that control particle emission.
 	 *
@@ -45,29 +52,25 @@ public:
 		//! position of the emitter
 		vec2 position;
 		//! maximum number of particles
-		const unsigned int max_particles = 0;
-		//! rate of particle emission per update (Lowest value = 0.001 any lower is ignored)
-		double emission_rate = 0;
+		const unsigned int max_particles = 256;
+		//! rate of particle emission per second
+		float emission_rate = 50;
 		//! min speed of the particles
-		double min_speed = 0;
+		float min_speed = 100;
 		//! min speed of the particles
-		double max_speed = 0;
+		float max_speed = 100;
 		//! min angle of particle emission
-		double min_angle = 0;
+		float min_angle = 0;
 		//! max angle of particle emission
-		double max_angle = 0;
-		//! begin Lifespan of particle (only visual)
-		double begin_lifespan = 0.0;
-		//! end Lifespan of particle
-		double end_lifespan = 0.0;
+		float max_angle = 0;
+		//! begin Lifespan of particle in seconds (only visual)
+		float begin_lifespan = 0.0;
+		//! end Lifespan of particle in seconds
+		float end_lifespan = 10.0;
 		//! force over time (physics)
 		vec2 force_over_time;
 		//! particle boundary
 		Boundary boundary;
-		//! collection of particles
-		std::vector<Particle> particles;
-		//! sprite reference
-		const Sprite & sprite;
 	};
 
 public:
@@ -75,11 +78,27 @@ public:
 	 * \param game_object_id  Identifier for the game object using this emitter.
 	 * \param data            Configuration data defining particle properties.
 	 */
-	ParticleEmitter(game_object_id_t game_object_id, const Data & data);
+	ParticleEmitter(game_object_id_t game_object_id, const Sprite & sprite, const Data & data);
 
 public:
 	//! Configuration data for particle emission settings.
 	Data data;
+
+protected:
+	virtual std::unique_ptr<Component> save() const;
+	ParticleEmitter(const ParticleEmitter &) = default;
+	virtual void restore(const Component & snapshot);
+	virtual ParticleEmitter & operator=(const ParticleEmitter &);
+
+private:
+	//! Only ParticleSystem can move and read particles
+	friend ParticleSystem;
+	//! Only RenderSystem can read particles
+	friend RenderSystem;
+	//! Saves time left over from last update event.
+	float spawn_accumulator = 0;
+	//! collection of particles
+	std::vector<Particle> particles;
 };
 
 } // namespace crepe
diff --git a/src/crepe/api/Script.cpp b/src/crepe/api/Script.cpp
index 753a9e3..cafc636 100644
--- a/src/crepe/api/Script.cpp
+++ b/src/crepe/api/Script.cpp
@@ -25,3 +25,26 @@ void Script::set_next_scene(const string & name) {
 }
 
 SaveManager & Script::get_save_manager() const { return this->mediator->save_manager; }
+
+void Script::replay::record_start() {
+	ReplayManager & mgr = this->mediator->replay_manager;
+	return mgr.record_start();
+}
+
+recording_t Script::replay::record_end() {
+	ReplayManager & mgr = this->mediator->replay_manager;
+	return mgr.record_end();
+}
+
+void Script::replay::play(recording_t recording) {
+	ReplayManager & mgr = this->mediator->replay_manager;
+	return mgr.play(recording);
+}
+
+void Script::replay::release(recording_t recording) {
+	ReplayManager & mgr = this->mediator->replay_manager;
+	return mgr.release(recording);
+}
+
+LoopTimerManager & Script::get_loop_timer() const { return this->mediator->loop_timer; }
+
diff --git a/src/crepe/api/Script.h b/src/crepe/api/Script.h
index 668e5d1..b052f8b 100644
--- a/src/crepe/api/Script.h
+++ b/src/crepe/api/Script.h
@@ -3,9 +3,12 @@
 #include <vector>
 
 #include "../manager/EventManager.h"
+#include "../manager/LoopTimerManager.h"
 #include "../manager/Mediator.h"
+#include "../manager/ReplayManager.h"
 #include "../system/CollisionSystem.h"
 #include "../types.h"
+#include "../util/Log.h"
 #include "../util/OptionalRef.h"
 
 namespace crepe {
@@ -46,9 +49,17 @@ protected:
 	/**
 	 * \brief Script update function (empty by default)
 	 *
+	 * \param delta_time Time since last fixed update
+	 *
 	 * This function is called during the ScriptSystem::update() routine if the \c BehaviorScript
 	 * component holding this script instance is active.
 	 */
+	virtual void update(duration_t delta_time) { return this->update(); }
+	/**
+	 * \brief Fallback script update function (empty by default)
+	 *
+	 * Allows the game programmer to ignore parameters passed to \c update()
+	 */
 	virtual void update() {}
 	//! \}
 
@@ -57,86 +68,108 @@ protected:
 
 protected:
 	/**
-	 * \name Utility functions
+	 * \name Component query functions
+	 * \see ComponentManager
 	 * \{
 	 */
-
 	/**
 	 * \brief Get single component of type \c T on this game object
-	 *
 	 * \tparam T Type of component
-	 *
 	 * \returns Reference to component
-	 *
 	 * \throws std::runtime_error if this game object does not have a component with type \c T
 	 */
 	template <typename T>
 	T & get_component() const;
-	// TODO: make get_component calls for component types that can have more than 1 instance
-	// cause compile-time errors
-
 	/**
 	 * \brief Get all components of type \c T on this game object
-	 *
 	 * \tparam T Type of component
-	 *
 	 * \returns List of component references
 	 */
 	template <typename T>
 	RefVector<T> get_components() const;
-
-	/**
-	 * \copydoc ComponentManager::get_components_by_id
-	 * \see ComponentManager::get_components_by_id
-	 */
+	//! \copydoc ComponentManager::get_components_by_id
 	template <typename T>
 	RefVector<T> get_components_by_id(game_object_id_t id) const;
-	/**
-	 * \copydoc ComponentManager::get_components_by_name
-	 * \see ComponentManager::get_components_by_name
-	 */
+	//! \copydoc ComponentManager::get_components_by_name
 	template <typename T>
 	RefVector<T> get_components_by_name(const std::string & name) const;
-	/**
-	 * \copydoc ComponentManager::get_components_by_tag
-	 * \see ComponentManager::get_components_by_tag
-	 */
+	//! \copydoc ComponentManager::get_components_by_tag
 	template <typename T>
 	RefVector<T> get_components_by_tag(const std::string & tag) const;
+	//! \}
 
 	/**
-	 * \brief Log a message using Log::logf
-	 *
-	 * \tparam Args Log::logf parameters
-	 * \param args  Log::logf parameters
+	 * \name Logging functions
+	 * \see Log
+	 * \{
 	 */
-	template <typename... Args>
-	void logf(Args &&... args);
+	//! \copydoc Log::logf
+	template <class... Args>
+	void logf(const Log::Level & level, std::format_string<Args...> fmt, Args &&... args);
+	//! \copydoc Log::logf
+	template <class... Args>
+	void logf(std::format_string<Args...> fmt, Args &&... args);
+	// \}
 
 	/**
-	 * \brief Subscribe to an event with an explicit channel
-	 * \see EventManager::subscribe
+	 * \name Event manager functions
+	 * \see EventManager
+	 * \{
 	 */
+	//! \copydoc EventManager::subscribe
 	template <typename EventType>
 	void subscribe(const EventHandler<EventType> & callback, event_channel_t channel);
-	/**
-	 * \brief Subscribe to an event on EventManager::CHANNEL_ALL
-	 * \see EventManager::subscribe
-	 */
+	//! \copydoc EventManager::subscribe
 	template <typename EventType>
 	void subscribe(const EventHandler<EventType> & callback);
+	//! \copydoc EventManager::trigger_event
+	template <typename EventType>
+	void trigger_event(const EventType & event = {},
+					   event_channel_t channel = EventManager::CHANNEL_ALL);
+	//! \copydoc EventManager::queue_event
+	template <typename EventType>
+	void queue_event(const EventType & event = {},
+					 event_channel_t channel = EventManager::CHANNEL_ALL);
+	//! \}
 
 	/**
-	 * \brief Set the next scene using SceneManager
-	 * \see SceneManager::set_next_scene
+	 * \name Scene-related functions
+	 * \see SceneManager
+	 * \{
 	 */
+	//! \copydoc SceneManager::set_next_scene
 	void set_next_scene(const std::string & name);
+	//! \}
 
+	/**
+	 * \name Save data management functions
+	 * \see SaveManager
+	 * \{
+	 */
 	//! Retrieve SaveManager reference
 	SaveManager & get_save_manager() const;
-
 	//! \}
 
+	//! Replay management functions
+	struct replay { // NOLINT
+		//! \copydoc ReplayManager::record_start
+		void record_start();
+		//! \copydoc ReplayManager::record_end
+		recording_t record_end();
+		//! \copydoc ReplayManager::play
+		void play(recording_t);
+		//! \copydoc ReplayManager::release
+		void release(recording_t);
+
+	private:
+		OptionalRef<Mediator> & mediator;
+		replay(OptionalRef<Mediator> & mediator) : mediator(mediator) {}
+		friend class Script;
+	} replay{mediator};
+
+	//! Retrieve LoopTimerManager reference
+	LoopTimerManager & get_loop_timer() const;
+
 private:
 	/**
 	 * \brief Internal subscribe function
diff --git a/src/crepe/api/Script.hpp b/src/crepe/api/Script.hpp
index 225a51c..4462a41 100644
--- a/src/crepe/api/Script.hpp
+++ b/src/crepe/api/Script.hpp
@@ -1,6 +1,7 @@
 #pragma once
 
 #include "../manager/ComponentManager.h"
+#include "../manager/ReplayManager.h"
 
 #include "BehaviorScript.h"
 #include "Script.h"
@@ -23,9 +24,14 @@ RefVector<T> Script::get_components() const {
 	return this->get_components_by_id<T>(this->game_object_id);
 }
 
-template <typename... Args>
-void Script::logf(Args &&... args) {
-	Log::logf(std::forward<Args>(args)...);
+template <class... Args>
+void Script::logf(const Log::Level & level, std::format_string<Args...> fmt, Args &&... args) {
+	Log::logf(level, fmt, std::forward<Args>(args)...);
+}
+
+template <class... Args>
+void Script::logf(std::format_string<Args...> fmt, Args &&... args) {
+	Log::logf(fmt, std::forward<Args>(args)...);
 }
 
 template <typename EventType>
@@ -34,8 +40,18 @@ void Script::subscribe_internal(const EventHandler<EventType> & callback,
 	EventManager & mgr = this->mediator->event_manager;
 	subscription_t listener = mgr.subscribe<EventType>(
 		[this, callback](const EventType & data) -> bool {
+			// check if (parent) BehaviorScript component is active
 			bool & active = this->active;
 			if (!active) return false;
+
+			// check if replay manager is playing (if initialized)
+			try {
+				ReplayManager & replay = this->mediator->replay_manager;
+				if (replay.get_state() == ReplayManager::PLAYING) return false;
+			} catch (const std::runtime_error &) {
+			}
+
+			// call user-provided callback
 			return callback(data);
 		},
 		channel);
@@ -52,6 +68,18 @@ void Script::subscribe(const EventHandler<EventType> & callback) {
 	this->subscribe_internal(callback, EventManager::CHANNEL_ALL);
 }
 
+template <typename EventType>
+void Script::trigger_event(const EventType & event, event_channel_t channel) {
+	EventManager & mgr = this->mediator->event_manager;
+	mgr.trigger_event(event, channel);
+}
+
+template <typename EventType>
+void Script::queue_event(const EventType & event, event_channel_t channel) {
+	EventManager & mgr = this->mediator->event_manager;
+	mgr.queue_event(event, channel);
+}
+
 template <typename T>
 RefVector<T> Script::get_components_by_id(game_object_id_t id) const {
 	Mediator & mediator = this->mediator;
diff --git a/src/crepe/api/Sprite.cpp b/src/crepe/api/Sprite.cpp
index ba684ba..0107c7b 100644
--- a/src/crepe/api/Sprite.cpp
+++ b/src/crepe/api/Sprite.cpp
@@ -1,6 +1,6 @@
 #include <cmath>
 
-#include "../util/Log.h"
+#include "../util/dbg.h"
 #include "api/Asset.h"
 
 #include "Component.h"
diff --git a/src/crepe/api/Transform.cpp b/src/crepe/api/Transform.cpp
index a85b792..fcfce14 100644
--- a/src/crepe/api/Transform.cpp
+++ b/src/crepe/api/Transform.cpp
@@ -1,8 +1,9 @@
-#include "../util/Log.h"
+#include "../util/dbg.h"
 
 #include "Transform.h"
 
 using namespace crepe;
+using namespace std;
 
 Transform::Transform(game_object_id_t id, const vec2 & point, double rotation, double scale)
 	: Component(id),
@@ -11,3 +12,11 @@ Transform::Transform(game_object_id_t id, const vec2 & point, double rotation, d
 	  scale(scale) {
 	dbg_trace();
 }
+
+unique_ptr<Component> Transform::save() const {
+	return unique_ptr<Component>{new Transform(*this)};
+}
+
+void Transform::restore(const Component & snapshot) {
+	*this = static_cast<const Transform &>(snapshot);
+}
diff --git a/src/crepe/api/Transform.h b/src/crepe/api/Transform.h
index 7ee6d65..a6f3486 100644
--- a/src/crepe/api/Transform.h
+++ b/src/crepe/api/Transform.h
@@ -35,6 +35,12 @@ protected:
 	virtual int get_instances_max() const { return 1; }
 	//! ComponentManager instantiates all components
 	friend class ComponentManager;
+
+protected:
+	virtual std::unique_ptr<Component> save() const;
+	Transform(const Transform &) = default;
+	virtual void restore(const Component & snapshot);
+	virtual Transform & operator=(const Transform &) = default;
 };
 
 } // namespace crepe